There's a vast gulf between a soup kitchen somewhere cheap and a sit-down restaurant in the middle of the city with high quality but high rents and high wages.

McDonalds is still going to exist and be cheap enough to eat at a lot.

Hole in the walls, with relatively cheap rents and family owned with takeout and streamlined overhead will also still exist.

>Eating out is strangely expensive in most places in the US, compared to many parts of Asia at least. I'm not sure why. I considered density as a factor but if anything cities cost more in the US.

The same reason everything is more expensive in the US; overhead and wages. The economics of running a family restaurant in a building you've owned for generations is completely different than that of a corporate fast casual place that pays wages and rent.